Ladder



March 1959 P. H. BUTTERMORE ET AL 2 8 LADDER Filed Dec. 14, 1956 Fig.2

F/'g./ U F/g.3 v q /4 9 9 /4 I A /5 /0 45 /7 7 7 I 1 /2 Provance H. Bur/armor:

Robert 5. Field IN VEN TORS Uflitfid. StatesPaW F 2,875,935 LADDER Provance HrButtermore, Painesville, Ohio, and

Robert S. Field, Palm Springs, Calif.

Application December 14, 1956, Serial'No. 628,261 1 Claim. (Cl. 22836) The present invention relates to new and useful im- 2,875,935 Patented Mar. 3, 1959 ice i the rungs 13. The rungs 13 pivotally connect the rails 7 provements in straight ladders and has for its primary object to provide, in a manner as hereinafter set forth, a ladder of this type which may be expeditiously folded or collapsed for storage or transport.

Another very important object of the invention is to provide a ladder of the aforementioned character com prising an extension which may be readily brought into use if needed.

Still another important object of the invention is to provide, in a collapsible straight ladder and an extension therefor, novel means for removably but firmly securing the extension in position on the ladder.

Other objects of the invention are to provide a ladder of the character set forth which will be comparatively simple in construction, strong, durable, compact, of light weight and which may be manufactured at low cost.

These together with other objects and advantages which will become subsequently apparent reside .in the details of construction and operation as more fully hereinafter described and claimed, reference being had to Figure 2' is a front elevational view, showing the ladder folded or collapsed;

Figure 3 is an enlarged view in horizontal section, taken substantially on the line 3-3 of Figure 1;

Figure 4 is anenlarged fragmentary view in transverse section, taken substantially on the line 4-4 of Figure 1;

Figure 5 is a fragmentary view in vertical section, taken substantially on the line 5--5 of Figure 4; and

Figure 6 is an enlarged view in front elevation and partially in vertical-section, showing an extension mounted on the ladden Referring now to the drawing in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a pair of side rails of magnesium, aluminum or other suitable material which are designated generally by reference character 7. The rails 7, which may also be of any desired dimensions, are in the form of opposed channel bars, said side rails including webs 8 and flanges 9. Braces 10 are provided between the opposed flanges 9 at suitably spaced pointsin the rails 7. The upper ends of the flanges 9 have formed therein notches or recesses 11.

Also mounted between the opposed flanges 9 at longitudinally spaced points on the rails 7 are headed metallic pins or shafts 12. Tubular rungs 13 have their end portions journaled on the shafts 12. Spacers 14 are mounted on the shafts 12 between the rungs 13 and flanges 9. Thrust bearings 15 in the form of washers are mounted on the shafts 12 between the spacers 14 and v for the reception of the end Removably mounted on 'tion of Figure 2 of the drawing forswinging movement in parallelism.

' The upper'end portions of the rails 7 have formed in the webs 8 thereof circular openings 16 (see Figure 6) portions of a removable tubular "rung 17. The" projecting end portions'of the rung 17 are apertured for the reception of cotter pins 18 for securing said rung 17 in position on the rails 7. The removable rung 17 secures the rails 7 in open position against swinging movement.

The members 7, 13, 17, etc., provide a straight ladder which is designated generally by reference character 19.

the upper end portion of the ladder 19 is an extension 20. The extension 20 includes a pair of substantially channel-shaped side rails 21 the lower end portions of which are slidably insertable downwardly in the upper end portions of the ladder rails 7. Circular openings in the webs of the rails 21 accommodate the removable rung 17 of the ladder 19. Tubular rungs 22, substantially similar to the rungs 13, have their end portions journaled on headed pins or shafts 23 which are mounted between the flanges of the rails 21. The

pins or shafts 23 and 12 are also substantially similar. The lower ends of the flanges of the rails 21 have formed therein notches or recesses 24 for the reception of the uppermost pins or shafts 12 of the ladder 19. The heads 25 of the pins or shafts 23 are engageable in the notches or recesses 11 in the upper ends of the ladder rails 7.

It is thought that the invention will be readily understood from a consideration of the foregoing. Briefly, with the removable rung 17 in position in the upper end portion of the ladder 19, said ladder is positively secured in open position for use. By removing the rung 17 the ladder 19 may be readily folded or collapsed to the posiwith the opposed side rails 7 in abutting engagement with each other. To use the extension 20, the ladder 19 is opened and the lower end portions of the rails 21 are engaged in the upper end portions of the rails 7, the notches or recesses 24 receiving the uppermost shafts 12, the heads 25 of the shafts 23 engaging in the notches or recesses 11 in the upper ends of the flanges 9. The rung 17 is then inserted through the rails 7 and 21 and the cotter pins 18 are inserted in the end portions of said rung for securing the assembly. 0f course,-to remove the extension 20 the foregoing procedure is substantially reversed. If desired, suitable removable shoes or boots may be provided on the lower end portions of the rails 7.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

A collapsible ladder comprising: a pair of opposed, substantially channel-shaped side rails, said side rails including a web and opposed flanges integral with said web, said flanges having notches in one end thereof, shafts extending between the flanges ofthe rails, tubular rungs having their end portions journaled on said shafts and spaced from said webs for pivotally connecting the side rails for swinging of said rungs on said shafts in opposite directions to fold the ladder, and a collapsible extension removably mounted on the ladder, said extension comprising substantially channel-shaped side rails engageable in certain end portions of the ladder rails, shafts mounted between the flanges of the extension rails, cer- 3 I i tain of the second named shafts including-heads-on their Reference's Clted in the fil'e ofthisp'atent" ends engageable in the notches of the ladder, tubular v STATES PATENTS rungs having their end portions journaled on the second named shafts for pivotally connecting the extension rails, 184'395 Lofiand 1876 said extension rails havingnotches in the lower end 5 'i g portions'thereof for thereception-oftheuppermost of the- 1 14O281 05 e a i 1915 first named shafts, and-means for positively connecting-- 0 ay the extensiontothe ladder, said ladder and extensiorrrails FOREIGN PATENTS having'aligned' openings: therein, saidtmeans'comprising a: 3,083 Great B i i 1 50 removable runghaving its en'd'portions fixedin the open 10 213,900 Great Britain: Ju 18, 1925 in gs. 1,012,784 France Apr. 23, 1952 

